Electronic modules are basically self-contained functional units that are used to create a larger system. Electronic modules may be situated on a separate base or portion to allow a user to systematically test for error, quickly replace a failed module, and in this particular case, effectively dissipate heat. The bottom-most portion of an electronic module may be comprised of a material that quickly dissipates or collects heat in order to divert it away from the electronic modules, which are the source of the heat. This heat dissipating component of the electronic module is preferably metallic in nature. The greater the surface area of the metallic component of the electronic module, the faster it can dissipate heat. However, certain applications require modules that are only capable of housing a few components. In those situations, not only is the dispersion of heat required, but the dispersion must be highly efficient or at least capable of diverting the heat without damage to the components. In certain applications, hundreds of Amps of electricity may pass through an electric component and if not cooled, can reach a temperature of about ninety (90) degrees Celsius, a temperature close to the degradation temperature of the electronics in the module. In these cases, the base of the module must be extremely efficient at dissipating heat in order for the electronic components not to prematurely fail or burn out. Moreover, this dissipation of heat allows the components to function properly.
Existing electronic modules are attached to a variety of devices, such as printed circuit boards (PCBs), housings, objects, etc., usually by screws, typically positioned at the corners of the electronic module. If the electronic modules produce a large amount of heat, the electronic modules are placed on and in contact with heat sinks, which assist the electronic module in the dispersion of the heat. Moreover, when electronic modules become hot due to the heat created by the components, the electronic modules tend to bow and bend creating a gap between the electronic module and the object it is resting on, as shown, but not drawn to scale, in FIG. 6. This gap may be a small numeric value, but in certain instances, this gap can cause hot spots to form on the electronic module. These hot spots, if not alleviated quickly, may have negative consequences such as burning out or premature failure of the electronic components.
Larger and thicker electronic modules are able to quickly and more efficiently dissipate heat created by components. However, while larger and thicker electronic modules may be more desirable, certain devices and applications may require smaller and thinner electronic modules because of space restraints. Smaller and thinner electronic modules will begin to bow at a smaller change in temperature when compared to a larger and thicker electronic module. This means that smaller and thinner electronic modules will begin to bow sooner, thereby creating hot spots, at a earlier time than larger and thicker electronic modules under the same circumstances and environment.
Another factor of electronic module bowing is the inherent nature of electronic module manufacturing. Electronic modules are not manufactured perfectly level or even, thereby creating a “bowed” electronic module. When these “bowed” modules are placed on a heat sink, an initial gap is formed between the module and the heat sink. Currently, conventional methods of securing an electronic module to a heat sink do not reduce the gap created between the module and the heat sink. Moreover, when a module is secured to a heat sink by fasteners, the clamping force created by each fastener may not be equal, creating asymmetrical clamping forces throughout the module. This uneven distribution of clamping forces causes the electronic module to bow, thereby diminishing the surface area of the module that contacts the heat sink. This reduction in contact surface area decreases the amount of heat that flows from the electronic module to the heat sink, and in so doing, overheating components that are attached to the module.
As stated above, this bow or gap that is created decreases the amount of heat that is dissipated from components in the region of bowing or phrased alternatively, where the contacting engagement is with less force, which then overheats. Moreover, certain materials tend to bow quicker than other materials because of their innate properties, particularly attributable to their thermal expansion coefficient. Depending on the material's thermal expansion coefficient, the material may bow faster or slower than a material that has a different thermal expansion coefficient. Nevertheless, manufacturing processes, asymmetrical clamping forces, the quantity, position on the electronic module, and surrounding temperature of components on an electronic module greatly affect the characteristics and rate at which the electronic module bows. Therefore, what is needed is an electronic module that may utilize at least one center mounting fastener in an interior region of the module in order to more effectively dissipate the heat created by components by maintaining forceful contiguous contact with an underlying heat sink.
Further limitations and disadvantages of conventional, traditional, and proposed approaches will become apparent to one of skill in the art, through comparison of such systems and methods with certain embodiments the claimed invention as set forth in the remainder of the present application with reference to the drawings.